Heat exchange unit

ABSTRACT

A carrier forms a drum-shaped housing having opposite open ends and a plurality of air-flow apertures. A support extends across one of the open ends and an axial blower with its associated drive is located within the housing. A spirally convoluted heatexchanger unit is located at the other end of the housing so that air aspirated by the blower passes into the housing in contact with the heat-exchanger unit.

United States Patent 1191 Luderssen 1 Mar. 26, 1974 [54] HEAT EXCHANGEUNIT 1,892,303 12/1932 Hagen 415/183 Inventor: g se Bre ger egy2,044,832 6/1936 Child 62/426 Germany [73] Assignee: Robert BoschHausgeraete GmbH, i y Examiner charle5 Myhre Gi Germany AssistantExaminer-Theophil W. Streule, Jr. Attorney, Agent, or Firm-Michael S.Striker [22] Flledz June 29, 1972 [21] Appl. No.1 267,711

[57] ABSTRACT [30] Foreign Application Priority Data July 21, 1971Germany 2136369 A carrier forms a drum-shaped housing having oppositeopen ends and a plurality of air-flow apertures. A [52] US. Cl. 165/122,62/426 support extends across one of the open ends and an [51] Int. Cl.F24h 3/08 axial blower with its associated drive is located within [58]Field of Search 165/122-126; the housing, A spirally convolutedheat-exchanger unit 10, 247; 15/1 3 is located at the other end of thehousing so that air aspirated by the blower passes into the housing in[56] References Cited contact with the heat-exchanger unit.

UNITED STATES PATENTS 3,089,314 5/1963 Speaker 62/288 9 Claims, 3Drawing Figures IENTEDmzs Ian SHEET 1 [IF 3 PAIENTED HARZS I974 SHEET 3OF 3 Fig.3

I-IEAT EXCHANGE UNIT BACKGROUND OF THE INVENTION The present inventionrelates generally to a heat exchange unit and particularly to a heatexchange unit which is especially suitable for use in air conditioners.Still more particularly, the invention relates to a heatexchange unitwhich is particularly suited for use in room air conditioner units.

Heat exchange unit particularly those used in roomtype air conditioners(as opposed to air conditioners which condition entire structures) areusually provided with a substantially flat box shaped case ofrectangular outline. The heat exchangers are in form of tubes which areaccommodated in the case in meander-shaped configuration and providedwith fins. However, this type of heat exchange unit requires arelatively large amount of space and because of this it necessarilyinfluences generally speaking, in a disadvantageous manner thedimensions and configuration of the entire air conditioner. It isnecessary under such circumstances to provide the air conditioner itselfof box-shaped outline. As

a result most of the air conditioners and their associated heat exchangeunits are relatively large and bulky.

This type of air conditioner unit and of heat exchanger thereforerequires a substantial amount of material and this of course increasesthe expenses of manufacturing such units. Moreover, it has been foundthat the relationship between cooling capacity and size of such units ishighly disadvantageous, particularly when the heat exchange unit isemployed in an air conditioner of the room-type that is which isintended to cool individual rooms.

One particular type of room air conditioner is the type which isintended to be installed in windows. When such air conditioners are ofbox-shaped outline, determined by the box-outline of the heat exchangeunit thereof, difficulites are often experienced when they are to beinstalled in the window, particularly in a casement window. In suchcases, a window pane must frequently be provided with a cutout, usuallya circular cutout for reasons of simplicity of forming the cut, in orderto accommodate an air guide baffle which is provided at the outlet side(the side where warm air is expelled) of the heat exchange unit. Suchbaffles necessarily increase the expenses in terms of material andassembly, as well as complicating the final installation.

Attempts have been made to overcome these difficulties by providing heatexchange units having evaporators of substantially cylindricalconfiguration, because here the relationship between the spacerequirement and the capacity can be chosen substantially moreadvantageous than in the other type of construction. However, heretoforeheat exchange units utilizing such cylindrical evaporators are ofcomplicated and expensive construction, thus being even more expensivethan the box-shaped type, and in addition requiring complicated andexpensive installation and servicing.

SUMMARY OF THE INVENTION It is, accordingly, a general object of thepresent invention to overcome the disadvantages of the prior art.

More particularly, it is an object of the present invention to providean improved heat exchange unit particularly a heat exchange unit suitedfor use in air conditioners which overcomes these disadvantages.

Another object of the invention is to provide such a heat exchange unitwhich can be economically manufactured.

Another object of the invention is to provide such a heat exchange unitwhich is simple to assemble and to install as well as being easy toservice and being compact in its dimensions.

Another object is to provide such a heat exchange unit having anadvantageous relationship between its dimensions and its capacity.

In pursuance of these objects and of others which will become apparenthereafter, one feature of the invention resides in a heat exchange unit,particular for use in air conditioners, which briefly stated comprisescarrier means forming a drum-shaped housing having opposite open endsand a plurality of air-flow apertures. Axial blower means and drivemeans therefore are both accommodated within the housing. Support meansis provided in the region of and extends across one of the open ends andspirally convoluted heat-exchanger means is provided on the housing inthe region of the other of the open ends thereof.

With this construction, and in particular with the carrier means forminga drum-shaped housing, an especially simple and compact dimensioning ofthe heatexchange unit is obtained.

According to a further advantageous concept of the invention, thehousing may be provided on its support means with substantially radiallyarranged ribs which extend at least approximately along the generatricesof an imaginary cylinder and which carry an annular body surrounding theaxial blower. This makes it possible to maintain the air gap between theblades of the axial blower and the annular body particularly small,which in turn provides for a highly efficacious guidance of the airbeing low in losses as well as in noise. Furthermore this constructionprovides for a concentric air aspiration which assures an even anduniform air flow.

The aforementioned ribs may also be provided on their outwardly directededges, which are at least substantially located at the outer diameter ofthe annular body, with a filter band which is annularly placed about thecarrier means and covers the air flow openings located between the ribsand delimited on the one hand by the support means and on the other handby the annular body. Such a construction provides for a particularlyreadily accessible arrangement of filter through which air is aspirated,making the construction especially economical and small as well aseffective.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an exploded perspective viewillustrating the essential components of a heat exchange unit accord-FIG. 3 is an end view of the heat exchange unit of FIGS. 1 and 2 withcertain components being broken away in order to partially make visibleother components located behind them.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing the drawing now indetail, it will be seen that reference numeral designates the heatexchange unit per se. Reference numeral 11 identifies a carrier unitwhich defines a drum-shaped housing of circular outline and havingopposite open ends. One of these ends is provided with a circularsupport plate 12 which is provided in the region of its outer marginaledge with an annulus of radially arranged ribs 13 extending along thegeneratrices of an imaginary cylinder. An additional annulus of ribs 14is also provided on the plate 12, located between the ribs 13. Anannular body 15 is carried on the ribs 13 and 14 at that end of the ribswhich faces away from the plate 12.

An annular circular opening is provided in the plate 12, at the base ofthe ribs 13 and 14, being identified with reference numeral 16 andpermitting the insertion of a non-illustrated, non-divided formingmandrel. The purpose of this is'to permit it to produce the element 11together with the plate 12 and the ribs 13 and 14 as a unitary componentfrom synthetic plastic material in a simple mold. Of course othermaterials than synthetic plastic may also be used.

Air inlet openings 17 are provided intermediate the ribs 13 and 14 andthe annular body 15 is provided in those portions which'delimit theopenings 17 in an arched configuration, analogous to a nozzle in orderto provide for advantageous deflection of the incoming air stream.

A bore 18 is provided in the plate 12 being coaxial with the centralaxis of the annular body and having a centering purpose which is to bedescribed subsequently.

A retaining portion 19 is provided on the outer marginal portion of theplate 12 being eccentric with reference to the central axis of theannular body 15 and having a purpose which is still to be discussed. Amounting plate portion 20 is of one piece with the plate 12, beinglocated at least substantially in the same plane as the latter and beingprovided in the region of maximum eccentricity, of the portion 19.

Accommodated in the housing or rather drumshaped housing is an axialblower 21 which is mounted on the output shaft of an electromotor 22.Reference to FIG. 2 will indicate that the motor 22 is provided with acentering portion 22' at that end which faces away from the output shaftand which centering portion is fitted with narrow tolerance into thebore 18 when the unit 10 is assembled. When this is done, the outputshaft of the motor 22 and thereby the axis of rotation of the blower 21is coaxial with the central axis of the annular body 15, assuring thatthe air gap between the annular body 15 and the outer tips of the bladesof the axial blower 21 can be maintained to the absolute minimumnecessary to assure that there will be no contact between them. Thisprovides for maximum air flow impelled by the blower at minimumdevelopment of noise.

The outer edges of the ribs 13 and 14 are substantially located on thesame circumferential line as the outer diameter of the annular body 15.They carry a filter tape 23 which is circularly placed about the body 15and which covers the openings 17 which are between the ribs 13 and 14and delimited by the plate 12 and the annular body 15, respectively. Thetape 14 can be retained in various ways, for instance by the holdingmember 24 illustrated in the drawing and being provided with pins or thelike which are pushed into the overlapping ends of the tape 23.

A heat exchange unit 25 is illustrated, being of spiral configurationand being provided on the annular body 15 at that end thereof whichfaces sway from the plate 12. The unit 25 is composed, as particularlyevident from FIG. 2, of a spirally convoluted tape or band provided withchannels 26 for cooling medium and being held together by a tensioningtape 27 which is shown separately in FIG. 1. The tape 27 is providedwith several brackets 28 which serve for engagement with devices 29provided at the outer circumference of the annular body 15, therebyretaining the unit 25 at the axial end of the latter. Screws 30 connectthe brackets 28 with the devices 29.

The tape 27 is further provided with a device 31 which engages and holdsa removable receptacle, here configurated as a bowl 32 or the like, forcondensate which drips off the unit 25. A conduit 33 is provided whichcommunicates with the interior of the bowl 32 and carries away thecondensate through the plate 12' to the exterior of the element 11.

Anchor members 34 are also provided on the tape 27, each carrying athreaded bolt 35 for engagement with nuts 36 which serve to retain aring 37 of a cover 38, the ring 37 being provided with a sieve likeportion.

It has previously been mentioned that there is provided a portion 19 onthe circumferential margin of the plate 12. The purpose of this portion19 is to hold and center that end of the cover 38 which faces away fromthe ring 37. The portion 19 is eccentrically offset with reference tothe central axis of the body 15 in the direction towards the plateportion 20. This assures that a rather large space exists between thebody 15 over the unit 25 and the cover 38, in which the bowl 32 isaccommodated.

The plate portion 20 which has also been mentioned earlier serves tocarry control and regulating devices for controlling and regulating theoperation of the heat exchange unit. Such devices are not a part of thepresent invention and are in any case conventional; for this reason theyhave not been illustrated and it is merely necessary to keep in mindthat they are to be mounted on the plate portion 20. A cap 39, removablysecured on the plate portion 20, provides protection for these deviceswhich are to be mounted on the same.

The individual components of the heat exchange unit according to thepresent invention are essentially carried by the element 11. Because ofthis it is possible to assemble the element 11 in a particularly simple,clearand economic manner. Moreover, servicing of the unit is especiallyeasy, and, because by removing the nuts 36 the cover 38 can be readilywithdrawn, affording access to the band 23 for cleaning or replacement,the unit can readily be serviced even by persons of no skill in the art,for instance by the average user.

The same considerations with reference to assembly and servicing werealso taken into account in the arrangement of the bowl 32 and theholding device 31 therefore. It is a simple matter to laterally shiftthe bowl 32 whereby the edge thereof is released by the device 31. Thebowl 32 is then lowered slightly at this side whereupon its oppositeside can also be released from the device 31 by lateral displacement indirection opposite to the previous movement. The bowl 32 can then beloweredin forward direction and can readily be cleaned in this positionwithout having to be separated from the flexible conduit 33.

When the unit according to the present invention is in operation, theaxial blower 31 aspirates air through the cover 38 which is perforatedor configurated as a grid-or the like. The aspirated air first flowsthrough the filter tape 23 at the openings 17 and is then made to flowover the heat exchange surfaces of the heat exchanger 25. Now cooled andcleaned of any relatively large contaminants it passes through thescreen portion of the ring 37. A part of the aspirated air stream willpass prior to its entry into the heat exchanger 25 over the regulatingdevices located beneath the cover 38 and thus assures that the deviceswill precisely and rapidly respond to varying temperature conditions.

The device which has been illustrated by way of example of FIGS. 1 3 isparticularly suitable for wall-installation. For this purpose the outerside of the plate 12 may be provided with eyes in which hooks mounted ina wall can be inserted. A second, similarly constructed unit can beconnected with the illustrated device, with the two plates 12 beingabutted, whereby a particularly compact but highly efficient airconditioner is created. Of course, other possibilities exist also, bothas to construction and to mounting. For instance, one of the two unitsso connected can be provided with a condenser or the mounting can beaffected in other manner.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in aheat exchange unit, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can be applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by letters Patent isset forth in the appended claims.

I claim:

1. A heat exchange unit, particularly for use in air conditioners,comprising carrier means forming a drum-shaped housing, said carriermeans comprising an annulus of circumferentially spaced substantiallyradially extending ribs forming between themselves a plurality ofradially extending air flow passages and an annular body integral withand projecting from one end of said annulus of ribs; axial blower meanscoaxially arranged within said annular body and comprising fan bladeshaving outer ends spaced with a minimum clearance from the inner surfaceof said annular body just sufficient to prevent contact between saidblades and said annular body; drive means for driving said blower meansarranged coaxially within said annulus of ribs; spirally convoluted heatexchanger means coaxially carried by said annular body on the endthereof facing away from said annulus of ribs; and support meansextending across the other end of said annulus of ribs for supportinsaid unit on a wall, said drive means being carried by said supportmeans, whereby during operation of said blower means air is suckedthrough said air passages and blown through said heat exchanger means ina direction away from said wall.

2. A unit as defined in claim 1, said ribs having outwardly directededges which at least substantially coincide with an outer diameter ofsaid annular body; and further comprising a strip of filter materialannularly surrounding said annular body and supported on said edges in aposition covering said air-flow passages.

3. A unit as defined in claim 1, said annular body having archedportions proximal to said airflow passages.

4. A unit as defined in claim 1, said support means comprising centeringmeans coaxial with the central axis of said annular body; and whereinsaid drive means comprises an electro motor having an output shaft and,at a side facing away from said blower means, a centering portion whichso engages said centering means that said output shaft is coaxial withsaid axis of said annular body.

5. A unit as defined in claim 1, said support means comprising an atleast substantially circular plate memher having an outer diametergreater than the outer diameter of said annular body and projectingradially outwardly thereof with an annular marginal portion; and whereinsaid marginal portion is configurated for engaging a cover surroundingsaid annular body.

6. A unit as defined in claim 5, wherein said marginal portion iseccentric relative to the central axis of said annular body.

7. A unit as defined in claim 6, wherein said cover surrounds saidannular body with clearance due to the eccentricity of said marginalportion; and further comprising a receptacle located in said clearancefor receiving condensate resulting from operation of said unit.

8. A unit as defined in claim 6, said plate member including in theregion of greatest eccentricity of said marginal portion a mountingportion for control elements of said unit, said mounting portion beinglocated substantially in the plane of said plate member.

Q. A unit as defined in claim 1, said annular body having an outerperiphery provided with engaging portions; further comprising aretaining tape surrounding said heat-exchanger means; and bracketsprovided on said tape and engaged by said engaging portions of saidannular body.

1. A heat exchange unit, particularly for use in air conditioners,comprising carrier means forming a drum-shaped housing, said carriermeans comprising an annulus of circumferentially spaced substantiallyradially extending ribs forming between themselves a plurality ofradially extending air flow passages and an annular body integral withand projecting from one end of said annulus of ribs; axial blower meanscoaxially arranged within said annular body and comprising fan bladeshaving outer ends spaced with a minimum clearance from the inner surfaceof said annular body just sufficient to prevent contact between saidblades and said annular body; drive means for driving said blower meansarranged coaxially within said annulus of ribs; spirally convoluted heatexchanger means coaxially carried by said annular body on the endthereof facing away from said annulus of ribs; and support meansextending across the other end of said annulus of ribs for supportinsaid unit on a wall, said drive means being carried by said supportmeans, whereby during operation of said blower means air is suckedthrough said air passages and blown through said heat exchanger means ina direction away from said wall.
 2. A unit as defined in claim 1, saidribs having outwardly directed edges which at least substantiallycoincide with an outer diameter of said annular body; and furthercomprising a strip of filter material annularly surrounding said annularbody and supported on said edges in a position covering said air-flowpassages.
 3. A unit as defined in claim 1, said annular body havingarched portions proximal to said airflow passages.
 4. A unit as definedin claim 1, said support means comprising centering means coaxial withthe central axis of said annular body; and wherein said drive meanscomprises an electro motor having an output shaft and, at a side facingaway from said blower means, a centering portion which so engages saidcentering means that said output shaft is coaxial with said axis of saidannular body.
 5. A unit as defined in claim 1, said support meanscomprising an at least substantially circular plate member having anouter diameter greater than the outer diameter of said annular body andprojecting radially outwardly thereof with an annular marginal portion;and wherein said marginal portion is configurated for engaging a coversurrounding said annular body.
 6. A unit as defined in claim 5, whereinsaid marginal portion is eccentric relative to the central axis of saidannular body.
 7. A unit as defined in claim 6, wherein said coversurrounds said annular body with clearance due to the eccentricity ofsaid marginal portion; and further comprising a receptacle located insaid clearance for receiving condensate resulting from operation of saidunit.
 8. A unit as defined in claim 6, said plate member including inthe region of greatEst eccentricity of said marginal portion a mountingportion for control elements of said unit, said mounting portion beinglocated substantially in the plane of said plate member.
 9. A unit asdefined in claim 1, said annular body having an outer periphery providedwith engaging portions; further comprising a retaining tape surroundingsaid heat-exchanger means; and brackets provided on said tape andengaged by said engaging portions of said annular body.